StarpTech

sub, err := sc.Subscribe("eventstore.events", func(m *stan.Msg) {
    fmt.Printf("Received a message: %s\n", string(m.Data))
    // your code
    if err := m.Ack(); err != nil {
       // event is redelivered
      return
    }
},
  stan.maxInFlight(1),
  stan.AckWait("30s"),

StarpTech

func (c *CommandBus) HandleCommand(cmd Command) {
  events := c.CommandHandler.HandleCommand(cmd)
  c.stan.Publish("eventstore.events", events)
}

StarpTech

// Subscribe starting with most recently published value
sub, err := sc.Subscribe("eventstore.events", func(m *stan.Msg) {
    fmt.Printf("Received a message: %s\n", string(m.Data))
}, stan.StartWithLastReceived())

// Receive all stored values in order
sub, err := sc.Subscribe("eventstore.events", func(m *stan.Msg) {
    fmt.Printf("Received a message: %s\n", string(m.Data))
}, stan.DeliverAllAvailable())

StarpTech

          id         |  last_processed_event_id   | processor_name   
+--------------------+----------------------------+-----------------+
  517800172974768129 | 01DXRWAVGFZ46AV38EA2CYXFQJ | reactor          
  517800173095550977 | 01DXRWAVGFZ46AV38EA2CYXFQJ | order-projector 

StarpTech

max_payload: 10485760
streaming {
  store: "SQL"
  sql_options: {
    no_caching: true
    driver: "postgres"
    source: "dbname=mydb host=roach1 port=26257 user=test sslmode=disable readTimeout=5s writeTimeout=5s"
  }
  store_limits {
    max_subs: 100

StarpTech

#!/usr/bin/env node
'use strict'

const inquirer = require('inquirer')
const bench = require('./lib/bench')
const { choices, list } = require('./lib/packages')
const argv = process.argv.slice(2)

async function select (callback) {
  const result = await inquirer.prompt([

StarpTech

// Inspired by https://www.robinwieruch.de/react-hooks-fetch-data/

const dataFetchReducer = (state, action) => {
  switch (action.type) {
    case 'REQUEST_INIT':
      return { ...state, isLoading: true, isError: false };
    case 'REQUEST_SUCCESS':
      return { ...state, isLoading: false, isError: false, data: action.payload };
    case 'REQUEST_FAILURE':
      return { ...state, isLoading: false, isError: true };

StarpTech

Graphql cache challenges

How to practice HTTP Caching?

GraphQL queries are usually POST requests. POST request aren't cached by nature. This means that we need different solutions to deliver our content efficiently.

• Apollo Server provide a apollo-cache-control in order to configure how long a query should be cached. Cache hint inside the schema.

• Automatic persisted queries (APQs) is a performance technique which allows a hash to be sent to the server instead of the entire GraphQL query string. It is possible to use APQs with GET requests here. In that way we can also benefit from CDN. How it works. In theory it's the same mechani

StarpTech

/**
 * Small library to validate numeric data structures in a functional-style
 * All functions are right associative
 * If you are looking for more sophisticated features have a look at
 * https://ramdajs.com/
 */

export interface FabPattern {
  [index: string]: (input: number) => boolean;
}

StarpTech

// initialize
// The maximum number of requests is equal to 
// maxSockets * 2 with keepAlive: true or equal to maxSockets with keepAlive: false.
const arangodb = new Arangojs.Database({
  url: "http://localhost:8529", // Base URL of the ArangoDB server or list of server URLs.
  agentOptions: {
    maxSockets: 100,
    keepAlive: true
  }, 
  loadBalancingStrategy: 'ROUND_ROBIN'